Sinclair Endow Vacuum Pump System. Overcome erectile difficulties with a vacuum therapy system that comes with two operating modes: an ergonomic hand pump and a battery operated pump. Connect with the 2 inch cylinder, slide your penis in and pump to engorge you penis to its maximum capacity, hardness and size. Set of 4 constriction rings maintain the erection for up to 30 minutes. Comes with 2 pumps with quick release valve, 10 inches long by 2 inches wide cylinder, removable gasket, connecting tubes, 4 constriction rings (.5 inch to .75 inch ), use and care directions. This pump is compatible with water based personal lubricant. It is not recommended to be used with silicone lubes. After use, carefully wash the pump with mild soap and water or try a sex toy cleaner for even quicker cleanup. Store this pump separately from other sex toys.